Two solid disks are both spinning on the same frictionless, vertical axle. The u

Question

Two solid disks are both spinning on the same frictionless, vertical axle. The upper disk is spinning clockwise at 450 rpm (rev/min), and the lower disk is spinning at 280 rpm (rev/min), counterclockwise. The upper disk is released, and it falls a few centimeters onto the lower disk. After the two disks couple together, their final angular velocity is 65 rpm, counterclockwise. If the moment of inertia of the lower disk is 4.8 kg m2, what is the moment of inertia of the upper disk? Apply the angular momentum conservation principle.

The moment of inertia is _____ kg m2.

Explanation / Answer

If x is moment of intertia of the upper disk, then

-450 x +280*4.8= (4.8 +x)*65

1344-450x= 312 +65x

515x= 1032.

x= 2.0 kg m^2

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.